Mozilla is offering new HTTP cache for Firefox from version 27 onwards -currently in Aurora, but disabled by default – you can enable this backend cache feature by switching value of preference ‘browser.cache.use_new_backend’toin ‘1’ about:config, you don’t need to restart the browser for the changes to take effect.
So Firefox now has Cache and Cache2 folders in hard drive. Cache2 is new cache backend. One bug is preventing Mozilla from turning this feature on by default, that is: when browser.cache.disk.capacity overreaches you’ve to manually clear those cache files using Clear Recent History dialog.
You can find the cache2 folder at the path-%LocalAppData%\Mozilla\Firefox\Profiles\profilename\cache2.
Clean or delete Firefox Cache2 files
Using ‘Clear Recent History’ dialog is one way of cleaning cache2 entries, other is through CCleaner. Yes! CCleaner’s latest version has added option for cleaning new cache location introduced in Firefox 27, you can turn thus feature on in Firefox and close the browser otherwise internet cache cleaning will be skipped.
Open CCleaner, and click on ‘Analyze’ button to show the details, when the results are shown, select and right click on ‘Firefox- internet cache’ and select ‘view detailed results’. You can see cache2 entries detected and shown by tool (check the screenshot below), go ahead and run CCleaner to delete them.
Happy Firefox cache2 cleaning.